I live in the suburbs. It's a solid 5-mile round trip to my closest local grocery store, with some hills. There's a drugstore about 2 mi round trip but they are expensive and don't have fresh food. Due to health problems I can make about 9-11 mph on the commuterized MTB, that would be the tractor. Not sure how much a trailer uphill would slow me further, but I imagine a lot. It could easily make for an hour of cycling. This has kept me from doing more with the bike rather than taking the car or truck.
How far do you travel with your cargo?